LXR linux/arch/s390/oprofile/backtrace.c

   1/**
   2 * arch/s390/oprofile/backtrace.c
   3 *
   4 * S390 Version
   5 *   Copyright (C) 2005 IBM Corporation, IBM Deutschland Entwicklung GmbH.
   6 *   Author(s): Andreas Krebbel <Andreas.Krebbel@de.ibm.com>
   7 */
   8
   9#include <linux/oprofile.h>
  10
  11#include <asm/processor.h> /* for struct stack_frame */
  12
  13static unsigned long
  14__show_trace(unsigned int *depth, unsigned long sp,
  15             unsigned long low, unsigned long high)
  16{
  17        struct stack_frame *sf;
  18        struct pt_regs *regs;
  19
  20        while (*depth) {
  21                sp = sp & PSW_ADDR_INSN;
  22                if (sp < low || sp > high - sizeof(*sf))
  23                        return sp;
  24                sf = (struct stack_frame *) sp;
  25                (*depth)--;
  26                oprofile_add_trace(sf->gprs[8] & PSW_ADDR_INSN);
  27
  28                /* Follow the backchain.  */
  29                while (*depth) {
  30                        low = sp;
  31                        sp = sf->back_chain & PSW_ADDR_INSN;
  32                        if (!sp)
  33                                break;
  34                        if (sp <= low || sp > high - sizeof(*sf))
  35                                return sp;
  36                        sf = (struct stack_frame *) sp;
  37                        (*depth)--;
  38                        oprofile_add_trace(sf->gprs[8] & PSW_ADDR_INSN);
  39
  40                }
  41
  42                if (*depth == 0)
  43                        break;
  44
  45                /* Zero backchain detected, check for interrupt frame.  */
  46                sp = (unsigned long) (sf + 1);
  47                if (sp <= low || sp > high - sizeof(*regs))
  48                        return sp;
  49                regs = (struct pt_regs *) sp;
  50                (*depth)--;
  51                oprofile_add_trace(sf->gprs[8] & PSW_ADDR_INSN);
  52                low = sp;
  53                sp = regs->gprs[15];
  54        }
  55        return sp;
  56}
  57
  58void s390_backtrace(struct pt_regs * const regs, unsigned int depth)
  59{
  60        unsigned long head;
  61        struct stack_frame* head_sf;
  62
  63        if (user_mode (regs))
  64                return;
  65
  66        head = regs->gprs[15];
  67        head_sf = (struct stack_frame*)head;
  68
  69        if (!head_sf->back_chain)
  70                return;
  71
  72        head = head_sf->back_chain;
  73
  74        head = __show_trace(&depth, head, S390_lowcore.async_stack - ASYNC_SIZE,
  75                            S390_lowcore.async_stack);
  76
  77        __show_trace(&depth, head, S390_lowcore.thread_info,
  78                     S390_lowcore.thread_info + THREAD_SIZE);
  79}
  80